Britannica Sources used in this answer

How does isostatic rebound occur after an ice sheet melts?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

esker: Nunavut — glacial landform Eskers, or narrow ridges of gravel and sand left by a retreating glacier, wind through western Nunavut, Canada, near the Thelon River.

Isostatic rebound is the process by which Earth's crust rises after the removal of a heavy load, such as a large ice sheet.1

During glaciation, the immense weight of an ice sheet causes the underlying crust to subside, a process facilitated by the flow of material within Earth's mantle. The extent of this depression is typically about one-third the thickness of the ice sheet itself.1

When the ice sheet melts, this weight is removed, triggering a compensatory uplift known as glacio-isostatic rebound. This movement follows a distinct pattern:1
* Initial Phase: The ground rises rapidly immediately following deglaciation.1
* Long-term Phase: The rate of uplift decreases over time as the crust approaches equilibrium.1

This process is not instantaneous; in regions like the eastern Hudson Bay, significant uplift has occurred over thousands of years, and the land continues to rise today at a rate of approximately 1.3 cm per year. Similar adjustments are observed in Fennoscandia, particularly around the Gulf of Bothnia.1